Shannon Richardson shot several times

A 25-year-old Boston man has pleaded not guilty to a murder charge in the fatal shooting of a one-time friend in Boston's Dorchester neighborhood.

Peter Carvalho was ordered held without bail at his arraignment Thursday.

Prosecutors said the 25-year-old victim, Shannon Richardson, was shot several times as he walked on Dudley street Wednesday afternoon, then collapsed in a nearby store. He was taken to a hospital, where he was pronounced dead.

Prosecutors said witnesses described Richardson's attacker. Patrol officers later saw Carvalho running and pursued him when they got a radio call about a shooting. He went into the same store where Richardson lay.

The Boston Globe reports that Richardson's mother wept during the court hearing. Some relatives and friends of both men said afterward they were friends who wouldn't have been violent toward each other.

Lawyers for Boston Marathon bomber Dzkokhar Tsarnaev rested their case in his federal death penalty trial Tuesday after presenting a brief case aimed at showing his late older brother was the mastermind of the 2013 terror attack.